diff options
| author | Björn Töpel <bjorn@rivosinc.com> | 2022-11-18 20:15:56 +0300 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2022-11-22 00:40:26 +0300 |
| commit | dd3553793a759e4f7f21c1aaffd5cb2de7a0068d (patch) | |
| tree | 313f8a5c8fb5db4d2a7cd21a6571046854d643a9 /Documentation/riscv | |
| parent | f13039ceec58a89f1457db5270a38b7ad4a9f07b (diff) | |
| download | linux-dd3553793a759e4f7f21c1aaffd5cb2de7a0068d.tar.xz | |
Documentation: riscv: Document the sv57 VM layout
RISC-V has been supporting the "sv57" address translation mode for a
while, but is has not been added to the VM layout documentation. Let
us fix that.
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20221118171556.1612190-1-bjorn@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/riscv')
| -rw-r--r-- | Documentation/riscv/vm-layout.rst | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst index 5b36e45fef60..3be44e74ec5d 100644 --- a/Documentation/riscv/vm-layout.rst +++ b/Documentation/riscv/vm-layout.rst @@ -97,3 +97,39 @@ RISC-V Linux Kernel SV48 ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel __________________|____________|__________________|_________|____________________________________________________________ + + +RISC-V Linux Kernel SV57 +------------------------ + +:: + + ======================================================================================================================== + Start addr | Offset | End addr | Size | VM area description + ======================================================================================================================== + | | | | + 0000000000000000 | 0 | 00ffffffffffffff | 64 PB | user-space virtual memory, different per mm + __________________|____________|__________________|_________|___________________________________________________________ + | | | | + 0100000000000000 | +64 PB | feffffffffffffff | ~16K PB | ... huge, almost 64 bits wide hole of non-canonical + | | | | virtual memory addresses up to the -64 PB + | | | | starting offset of kernel mappings. + __________________|____________|__________________|_________|___________________________________________________________ + | + | Kernel-space virtual memory, shared between all processes: + ____________________________________________________________|___________________________________________________________ + | | | | + ff1bfffffee00000 | -57 PB | ff1bfffffeffffff | 2 MB | fixmap + ff1bffffff000000 | -57 PB | ff1bffffffffffff | 16 MB | PCI io + ff1c000000000000 | -57 PB | ff1fffffffffffff | 1 PB | vmemmap + ff20000000000000 | -56 PB | ff5fffffffffffff | 16 PB | vmalloc/ioremap space + ff60000000000000 | -40 PB | ffdeffffffffffff | 32 PB | direct mapping of all physical memory + ffdf000000000000 | -8 PB | fffffffeffffffff | 8 PB | kasan + __________________|____________|__________________|_________|____________________________________________________________ + | + | Identical layout to the 39-bit one from here on: + ____________________________________________________________|____________________________________________________________ + | | | | + ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF + ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel + __________________|____________|__________________|_________|____________________________________________________________ |